the shipyard

[Seiya09]

Hello my name is pasquale and I am a student in mechanical engineering.
I was beginning to use ansys and I wanted to ask something about my doubt.
I have to do the analysis of a frame with various types of profiles: unp, angles, tubular, etc. the analysis is three-dimensional, use beam4 elements,beam44... My question is:
I have my frame built with keypoints and lines, a classic frame with rectangular shape, and I have angle profiles (like type) both for the support legs and for the upper base (so positioned vertically and horizontally), my doubt is:
I defined the type of beam element4. As for real constants, do I have to define two because of the different view of the angle section, so with different ix and iy depending on the direction? or just define a single real constants and ansys understands alone that the section is placed differently?
I hope I've been clear.
Thank you all for the answers.

 

[SOLID]

Do you need to calculate a 2d or 3d frame?

in general:
If you are doing a 3d analysis then you must define both moments of inertia and correctly orientate your element.
while if you are analyzing a flat frame and so you have to perform a 2d analysis then you have to use beam3 beam3 beam23 beam3 beam3 beam23 beam3 beam23 beam3 beam3 beam23 beam3 beam23 beam23 beam3 beam23 beam3 beam23 beam3 beam23 beam3 beam23 beam3 beam3 beam3 beam3 beam23 beam3 beam3 beam3 beam23 beam23 beam3 beam3 beam3 and here you can only define the izz.

 

[Seiya09]

Thank you for your prompt response.
the frame I have to analyze is in 3d (I have attached the image).
Let's make an example:
Let us suppose that element 1 is a profile facing downward and element 2 to u (same size) but facing left.
I do well if I realize a single element, for example beam4 and then I define a single real constants?
or should I define two real constants by changing the moments of inertia?
Thanks again.

 

[SOLID]

or should I define two real constants by changing the moments of inertia?

as first thing in my opinion if you provide a single moment of inertia will give you error the software (can not calculate the matrix of rigidity of the element), however in any case just try. . .

I write in general because I do not know ansis
when working with beam elements it is also necessary to define the local system of reference of the element (usually you choose by appropriately identifying 3 knots). This reference system besides identifying the axis of the element (x) also identifies how the section (y z) is oriented. therefore the properties of the section define them once only (area and moments of inertia regarding y and z) while with the definition of the reference systems establish the guidelines.

regarding the choice of the local reference system, please note that the start and end nodes identify the x axis (and the first node the origin); the y axis is chosen as a vector product between the vectors defined by the 1st and 2nd knot, and from the 1st and 3rd knot; while the z axis as a vector product between the x axis and y.
Please note that there are also other methods to identify the reference system. . .

 

[Seiya09]

thanks for the answer